Bicycles are one of the most popular means of transportation worldwide. They are easy to use and their maintenance is fairly inexpensive.
In cities, users may take the bicycle at one location and leave it at another location for a given amount of time. For instance, a bicycle user may leave his bicycle on the street or the sidewalk while running an errand in a store.
Unfortunately, when left unattended, especially in places accessible to a large numbers of persons, a bicycle may be subject to vandalism or even theft in the more extreme cases. One of the most frequent vandalism act performed on bicycles is the theft of the seat, also known in the art as saddle.
Generally, a bicycle comprises a seat attached to the upper end of a seat post. The seat post is telescopically inserted in a seat tube forming part of the bicycle frame, the seat tube defining a sleeve in which the seat post is received. To enable users with different body configurations to ride the bicycle, the seat post is slidable inside the seat tube. A user, prior to riding the bicycle, adjusts the height of the seat such that his feet may comfortably reach the bicycle pedals when he is riding the bicycle. Bicycle position selection means, such as a split collar system, are usually provided for selectively fastening and unfastening the seat post in the seat tube at the adjusted height.
In most bicycles, the lower end of the seat post is simply inserted in the upper end of the seat tube. This configuration facilitates the assembly of the seat to the bicycle. Unfortunately, this configuration also facilitates the theft of the bicycle seat. Indeed, by merely unfastening the seat post using the bicycle position selection means, a malevolent individual may raise the seat post in the seat tube until the lower end of the seat post is raised over the upper end of the seat tube, thereby removing the seat and seat post from the bicycle.
One way to avoid such act is for users to remove the seat from the bicycle and put the seat in a secure location, such as on their person, before leaving the bicycle unattended.
According to this solution, the users are faced with the burden of removing the seat from the seat tube of the bicycle and bringing the seat along with them wherever they go without the bicycle.
The skilled addressee will appreciate that this is a major drawback for the user since the user has to carry an item along with him. This situation is most impractical, especially if the user is leaving his bicycle unattended to run some errands.
International application WO2005/021364 by Tribout discloses a seat post locking device in which the height at which the seat post may be raised in the seat tube is limited. This device aims at preventing users from raising the seat over a certain level and running the risk of the lower end of the seat post or the upper end of the seat tube breaking while the user is riding the bicycle.
This device is specifically made to be used with a type of bicycle called full suspension bicycles. Such a bicycle is provided with a rear wheel suspension system located beneath the seat. The seat tube in such a bicycle therefore comprises a tube shorter than seat tubes used on other types of bicycles; in some of those bicycles, the seat tube further comprises an upper open end and a bottom open end.
More precisely, Tribout teaches of a device comprising a rod concentrically inserted in the seat post. This rod is slidably mounted to a fixing element and may slide through a central hole provided thereon. The fixing element is threadably mounted to the inside wall of the seat post. The rod further comprises a bulging head provided at its upper end and a spring wrapped around the upper end of the rod, the spring being caught between the bulging head and the fixing element. The lower end of the rod is fixedly mounted to a ring element comprising an abutting lip designed to abut the lower open end of the seat tube when the seat post is raised above a certain level.
When the seat is in its lowermost position, the lower end of the seat post and the ring element are positioned lower than the lower open end of the seat tube. When the seat is raised, the seat post, and therefore the rod, slides upwardly in the seat tube until the lip of the ring element abuts the lower end of the seat tube. The rod is then immobilized in this position, while the seat post may still slide upwardly. The skilled addressee will appreciate that when the rod is static and the seat post is slid upwardly, the spring is compressed. The seat post may thus be raised until the spring is maximally compressed, thereby preventing the seat post from being completely removed from the seat tube.
This device suffers from many shortcomings. For instance, in bicycles other than full suspension bicycles, the lower end of the seat tube is generally not open. If the device was installed on such a bicycle, it would be impossible for the lip of the ring element to abut the lower end of the seat tube and to limit the upward displacement of the rod.
Another shortcoming is that the installation of such a system requires access to the bottom end of the seat post once it has been inserted in the seat tube for securing the ring element to the bottom end of the rod. In a bicycle other than a full suspension bicycle, the bottom end of the seat post is inaccessible once it has been inserted in the seat tube, making the installation of such a device cumbersome.
Another shortcoming is that, if the lower end of the seat tube in fact comprises an open end, such as in some full suspension bicycles, the bottom end of the seat post will remain accessible to all after the device is installed in the bicycle. This unrestricted access to the bottom end of the seat post is a great disadvantage, since a malicious individual is free to tamper with it in order to remove the seat post from the seat tube and steal the saddle attached to the seat post.
Another shortcoming is that the outer surface of the bottom of the seat post may also be exposed to dirt, rain or any other source of natural damage, which is a great disadvantage as it may hinder the sliding of the seat post in the seat tube.
Another shortcoming is that the height at which the seat may be raised is limited by the characteristics of the spring being caught between the bulging head of the rod and the fixing element. The manufacturer of such system thus has to take into account the length of the maximally compressed spring when designing the seat post, making it longer then actually needed. This results in a great amount of material being wasted, which is not desirable.
Moreover, after the ring element has abutted the lower end of the seat tube, raising the seat post requires a great amount of strength from a user, as the compressed spring exerts a downward force on the seat post. This feature may become an issue and potentially lead to injuries.
There is therefore a need for an apparatus that will overcome at least one of the above-identified drawbacks.
Features of the invention will be apparent from review of the disclosure, drawings and description of the invention below.